Cover hub with sealing ring

ABSTRACT

A cover hub for a torque converter includes a radial wall arranged for axial alignment with a cover of the torque converter, a first circumferential surface including an opening for receiving a seal, and a second circumferential surface disposed radially inside of the first circumferential surface and arranged for sealing to a transmission input shaft. The hub has a first fluid passage exiting the hub at a first axial side of the opening and a second fluid passage, circumferentially offset from the first fluid passage and exiting the hub on a second axial side of the opening, opposite the first axial side, and a first circumferential protrusion for sealing the hub to the cover.

FIELD

The invention relates generally to a torque converter cover hub, and more specifically to a torque converter cover hub with a sealing ring.

BACKGROUND

Torque converter cover hubs are known. Examples are shown in U.S. Pat. No. 5,667,043 to Dehrmann et al. and commonly-assigned United States Patent Publication No. 2011/0120829 to Vanni et al.

BRIEF SUMMARY

Example aspects broadly comprise a cover hub for a torque converter including a radial wall arranged for axial alignment with a cover of the torque converter, a first circumferential surface including an opening for receiving a seal, and a second circumferential surface disposed radially inside of the first circumferential surface and arranged for sealing to a transmission input shaft. The hub has a first fluid passage exiting the hub at a first axial side of the opening, a second fluid passage, circumferentially offset from the first fluid passage and exiting the hub on a second axial side of the opening, opposite the first axial side, and a first circumferential protrusion for sealing the hub to the cover.

In an example embodiment, at least a portion of the first fluid passage intersects the radial wall or the second circumferential surface. In an example embodiment, at least a portion of the first or second fluid passage intersects the first circumferential surface. In an example embodiment, the hub includes a second circumferential protrusion, axially opposite of the first protrusion, for engaging a clutch seal plate.

Other example aspects broadly comprise a cover assembly for a torque converter including a cover having a first radial wall with a circumferential recess and a cover hub. The hub has a second radial wall with a first circumferential protrusion extending axially into the recess, a first circumferential surface arranged for sealing to a piston plate for the torque converter, a second circumferential surface disposed radially inside of the first circumferential surface and arranged for sealing to a transmission input shaft, and first and second fluid passages exiting the hub at the first circumferential surface.

In an example embodiment, the first circumferential surface includes an opening for receiving a seal, at least a portion of the first fluid passage extends from the radial wall or the second circumferential surface and exits the hub at a first axial side of the opening, and at least a portion of the second fluid passage exits the hub on a second axial side of the opening, opposite the first axial side. In an example embodiment, the hub is fixed to the cover by a discontinuous weld. In some example embodiments, the cover assembly includes a piston plate with a third circumferential surface and a seal disposed in the opening for sealing the third circumferential surface to the hub. In an example embodiment, the cover assembly includes a seal plate and the hub includes a second circumferential protrusion extending in an axially opposite direction from the first protrusion and fixed to the seal plate.

Other example aspects broadly comprise a torque converter including a cover assembly having a cover shell with a first continuous recess, and a cover hub. The cover hub is fixed to the shell by a discontinuous weld and includes a second continuous recess engaged with the first recess to seal the hub to the cover shell. The torque converter also includes a piston plate sealed to the cover hub and a seal plate fixed to the hub. In an example embodiment, the hub has a circumferential surface arranged for sealing to a transmission input shaft, a first passage extending from a first axial side of the circumferential surface, through the hub, to a chamber at least partially formed by the cover shell and the piston plate, and a second passage extending from a second axial side of the circumferential surface, opposite the first axial side, through the hub, to a chamber at least partially formed by the piston plate and the seal plate.

BRIEF DESCRIPTION OF THE DRAWINGS

The nature and mode of operation of the present invention will now be more fully described in the following detailed description taken with the accompanying drawing figures, in which:

FIG. 1A is a perspective view of a cylindrical coordinate system demonstrating spatial terminology used in the present application;

FIG. 1B is a perspective view of an object in the cylindrical coordinate system of

FIG. 1A demonstrating spatial terminology used in the present application;

FIG. 2 is a cross-section view of a top half of a prior art torque converter;

FIG. 3 is a detail view of boxed portion 3 in FIG. 2 with several components removed for clarity;

FIG. 4 is a detail view of an alternative embodiment of the hub and shell of FIG. 3 including a sealing ring shown before assembly;

FIG. 5 is a detail view of the hub and shell of FIG. 4 shown after assembly.

DETAILED DESCRIPTION

At the outset, it should be appreciated that like drawing numbers appearing in different drawing views identify identical, or functionally similar, structural elements. Furthermore, it is understood that this invention is not limited only to the particular embodiments, methodology, materials and modifications described herein, and as such may, of course, vary. It is also understood that the terminology used herein is for the purpose of describing particular aspects only, and is not intended to limit the scope of the present invention, which is limited only by the appended claims.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs. Although any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the invention, the following example methods, devices, and materials are now described.

FIG. 1A is a perspective view of cylindrical coordinate system 80 demonstrating spatial terminology used in the present application. The present invention is at least partially described within the context of a cylindrical coordinate system. System 80 has a longitudinal axis 81, used as the reference for the directional and spatial terms that follow. The adjectives “axial,” “radial,” and “circumferential” are with respect to an orientation parallel to axis 81, radius 82 (which is orthogonal to axis 81), and circumference 83, respectively. The adjectives “axial,” “radial” and “circumferential” also are regarding orientation parallel to respective planes. To clarify the disposition of the various planes, objects 84, 85, and 86 are used. Surface 87 of object 84 forms an axial plane. That is, axis 81 forms a line along the surface. Surface 88 of object 85 forms a radial plane. That is, radius 82 forms a line along the surface. Surface 89 of object 86 forms a circumferential plane. That is, circumference 83 forms a line along the surface. As a further example, axial movement or disposition is parallel to axis 81, radial movement or disposition is parallel to radius 82, and circumferential movement or disposition is parallel to circumference 83. Rotation is with respect to axis 81.

The adverbs “axially,” “radially,” and “circumferentially” are with respect to an orientation parallel to axis 81, radius 82, or circumference 83, respectively. The adverbs “axially,” “radially,” and “circumferentially” also are regarding orientation parallel to respective planes.

FIG. 1B is a perspective view of object 90 in cylindrical coordinate system 80 of FIG. 1A demonstrating spatial terminology used in the present application. Cylindrical object 90 is representative of a cylindrical object in a cylindrical coordinate system and is not intended to limit the present invention in any manner. Object 90 includes axial surface 91, radial surface 92, and circumferential surface 93. Surface 91 is part of an axial plane, surface 92 is part of a radial plane, and surface 93 is part of a circumferential plane.

The following description is made with reference to FIGS. 2-3. FIG. 2 is a cross-section view of a top half of a prior art torque converter. FIG. 3 is a detail view of boxed portion 3 in FIG. 2 with several components removed for clarity. Prior art torque converter 100 includes impeller 102, stator 104, and turbine 106 enclosed within a housing formed by cover shell 108 and impeller shell 110. During particular operating conditions of converter 100, clutch and damper assembly 112 may be hydraulically engaged as described below to bypass fluid operation of the impeller, stator, and turbine.

Cover assembly 114 includes shell 108 and cover hub 116 as shown in more detail in FIG. 3. Shell 108 includes radial wall 118 and cover hub 116 includes radial wall 120, axially aligned with wall 118. By axially aligned, we mean that the walls are lying adjacent to one-another. That is, they are touching. In an example embodiment, the shell and hub may be fixed together by continuous weld 122, for example, to maintain axial alignment of walls 118 and 120, and to seal hub 116 to cover 108.

Hub 116 includes circumferential surface 124 including opening 126 for receiving seal 128 (FIG. 2), for example, and surface 130 disposed radially inside of surface 124 and arranged for sealing to a transmission input shaft (not shown) at bushing 132 (FIG. 2), for example. Fluid passage 134 exits hub 116 to the right of opening 126 as shown in FIG. 3. Fluid passage 136 exits hub 116 to the left, or the opposite side, of opening 126 as shown in FIG. 3. Although passages 134 and 136 are shown in the same section view, it should be understood that the passages are circumferentially offset as evidenced by the dashed lines on passage 134 where the passages appear to intersect. That is, the fluid passages are independent of one another so that there is no fluid exchange from passage 134 to passage 136, or vice versa.

Clutch and damper assembly 112 includes piston plate 138, seal plate 140, and clutch pack 142. The clutch pack is clamped by the piston plate when pressure in chamber 144 between the piston plate and seal plate is higher than pressure in chamber 146 between the piston plate and the cover shell. Pressurized oil enters chamber 144 through passage 134, and chamber 146 through passage 136. Passage 136 may connect to the transmission through orifice 150 in hub 152 and a channel disposed between the input shaft and the stator shaft (not shown), for example. Passage 134 may connect to the transmission through a passage extending along the length of the input shaft, for example.

Seals 128 and 148, and piston 138 cooperate to divide chambers 144 and 146. Similarly, continuous weld 122 seals hub 116 to shell 108 so that pressurized oil directed from the input shaft channel to passage 134 to clamp the clutch cannot leak into chamber 146 by flowing between the hub and the shell. Similarly, the continuous weld prevents higher pressure oil in chamber 146 from leaking into passage 134 when the clutch is unlocked. A continuous weld is expensive and adds additional heat to the hub and shell that may result in distortion or warpage.

The following description is made with reference to FIGS. 4-5. FIG. 4 is a detail view of an alternative embodiment of the hub and shell of FIG. 3 including a sealing ring shown before assembly. FIG. 5 is a detail view of the hub and shell of FIG. 4 shown after assembly. Hub 216 includes circumferential surface 224 including opening 226 for receiving seal 128, for example, arranged for sealing to a piston plate (i.e., piston plate 138 in FIG. 2). Piston plate 138 includes circumferential surface 166. In an example embodiment (not shown), seal 128 is disposed in opening 226 for sealing surface 166 to hub 216. Hub 216 includes circumferential surface 230 disposed radially inside of surface 224 and arranged for sealing to a transmission input shaft in a manner similar to sealing of surface 130 described above.

Fluid passage 234 exits hub 216 to the right of opening 226 as shown in FIG. 4. Fluid passage 236 exits hub 216 to the left, or the opposite side, of opening 226 as shown in FIG. 4. Otherwise stated, passage 236 extends from the right axial side of circumferential surface 230, through hub 216, to chamber 146 (FIG. 2) at least partially formed by cover shell 208 and piston plate 138. Passage 234 extends from the left axial side of circumferential surface 230, through hub 216, to chamber 144 at least partially formed by piston plate 138 and seal plate 140

Although passages 234 and 236 are shown in the same section view, it should be understood that the passages are circumferentially offset as evidenced by the dashed lines on passage 234 where the passages appear to intersect. That is, the fluid passages are independent of one another so that there is no fluid exchange from passage 234 to passage 236, or vice versa.

Hub 216 includes circumferential protrusion, or sealing ring, 254 for sealing the hub to the cover. By circumferential protrusion, we mean that protrusion 254 is a continuous loop extending from radial surface 220. Portion 256 of passage 134 intersects radial wall 220 and circumferential surface 230. Portion 258 of passage 234 intersects circumferential surface 224. Although only portion 258 is shown to intersect surface 224, in other embodiments (not shown), portion 260 of passage 236 intersects surface 224. Hub 216 includes circumferential protrusion 262, axially opposite of protrusion 254, for engaging clutch seal plate 140 (FIG. 2). That is, in a torque converter assembly, seal plate 140 and hub 216 are fixed together at protrusion 262.

Cover 208 includes radial wall 218 with circumferential recess, or opening, 264. Similar to protrusion 254, recess 264 extends continuously in a circumferential direction from radial surface 218. As best shown in FIG. 5, circumferential protrusion 254 extends axially into recess 264. That is, the protrusion and recess are complementarily shaped such that the protrusion may be assembled into the recess with minimal clearance. Hub 216 is fixed to cover 208 by discontinuous weld 222. That is, weld 222 does not form a complete ring around hub 216 in the way that weld 122 forms a complete ring around hub 116 to seal the hub to the cover. Because hub 216 includes axial protrusion 254 fitted into cover recess 264, weld 222 does not need to seal the hub to the cover and can be a series of smaller welds that is less expensive and less prone to distortion when compared with a continuous weld. The tight fit between the hub protrusion and the cover recess acts to seal the components together to prevent fluid exchange as described above. That is, the minimal clearance creates a high resistance to fluid flow between the hub and cover, effectively sealing the hub to the cover.

Of course, changes and modifications to the above examples of the invention should be readily apparent to those having ordinary skill in the art, without departing from the spirit or scope of the invention as claimed. For example, although the protrusion and recess extend in a circumferential direction, they are not necessarily cylindrical in shape. For example, in some applications, the pair may have a polygonal shape with straight sides and rounded corners. This may be especially important if the particular application necessitates torque transmission through the hub because the polygonal shape limits the torque transmitted through the weld. Although the invention is described by reference to specific preferred and/or example embodiments, it is clear that variations can be made without departing from the scope or spirit of the invention as claimed. 

What we claim is:
 1. A cover hub for a torque converter comprising: a radial wall arranged for axial alignment with a cover of the torque converter; a first circumferential surface including an opening for receiving a seal; a second circumferential surface disposed radially inside of the first circumferential surface and arranged for sealing to a transmission input shaft; a first fluid passage exiting the hub at a first axial side of the opening; a second fluid passage, circumferentially offset from the first fluid passage and exiting the hub on a second axial side of the opening, opposite the first axial side; and, a first circumferential protrusion for sealing the hub to the cover.
 2. The cover hub of claim 1 wherein at least a portion of the first fluid passage intersects the radial wall or the second circumferential surface.
 3. The cover hub of claim 1 wherein at least a portion of the first or second fluid passage intersects the first circumferential surface.
 4. The cover hub of claim 1 wherein the hub includes a second circumferential protrusion, extending in a direction axially opposite of the first protrusion, for engaging a clutch seal plate.
 5. A cover assembly for a torque converter comprising: a cover including a first radial wall with a circumferential recess; and, a cover hub including: a second radial wall with a first circumferential protrusion extending axially into the recess; a first circumferential surface arranged for sealing to a piston plate for the torque converter; a second circumferential surface disposed radially inside of the first circumferential surface and arranged for sealing to a transmission input shaft; and, first and second fluid passages exiting the hub at the first circumferential surface.
 6. The cover assembly of claim 5 wherein: the first circumferential surface includes an opening for receiving a seal; at least a portion of the first fluid passage extends from the radial wall or the second circumferential surface and exits the hub at a first axial side of the opening; and, at least a portion of the second fluid passage exits the hub on a second axial side of the opening, opposite the first axial side.
 7. The cover assembly of claim 5 wherein the hub is fixed to the cover by a discontinuous weld.
 8. The cover assembly of claim 5 further comprising: a piston plate with a third circumferential surface; and, a seal disposed in the opening for sealing the third circumferential surface to the hub.
 9. The cover assembly of claim 8 further comprising: a seal plate, wherein the hub includes a second circumferential protrusion, extending in an axially opposite direction from the first protrusion and fixed to the seal plate.
 10. A torque converter comprising: a cover assembly including a cover shell with a first continuous recess and a cover hub, fixed to the shell by a discontinuous weld and including a second continuous recess engaged with the first recess to seal the hub to the cover shell; a piston plate sealed to the cover hub; and, a seal plate fixed to the hub.
 11. The torque converter of claim 10 wherein the hub further comprises: a circumferential surface arranged for sealing to a transmission input shaft; a first passage extending from a first axial side of the circumferential surface, through the hub, to a chamber at least partially formed by the cover shell and the piston plate; and, a second passage extending from a second axial side of the circumferential surface, opposite the first axial side, through the hub, to a chamber at least partially formed by the piston plate and the seal plate. 